With California utilities expanding rapidly into renewables, the Mojave Desert is one of the hottest spots for solar energy. Last year, plans for the world’s largest solar array got underway in this ideal energy harvesting setting and the latest news is just as groundbreaking. Pacific Gas and Electric recently signed the world’s largest solar deal to date, teaming up with BrightSource Energy to produce three new solar-thermal electric plants for a whopping 500 megawatts of clean green power. The $2 to $3 billion dollar deal provides options for additional plants (up to 900 megawatts total), which would be enough to power 375,000 Californian homes!
California law currently requires PG&E to produce 20% of its power via renewable sources by 2010, which is one of the factors driving this deal. The energy giant has been hard at work signing contracts, diversifying its renewable portfolio to include solar, wind, biomass, geothermal, and hydroelectric sources. Fong Wan, vice president of energy procurement, states “Solar-thermal energy is an especially attractive renewable power source because it is available when needed most in California - during the peak mid-day summer period.”
The arid expanse of California’s Mojave desert shows world-class potential for BrightSource’s solar technology, which utilizes thousands of mirrors to focus solar energy upon a boiler, where water is vaporized to to drive turbines. The solar-thermal plants will utilize Brightsource Energy’s proprietary Distributed Power Tower technology, which claims to be much more energy efficient than past parabolic trough designs.
The plants will employ thousands of tiny, flat movable mirrors called heliostats to focus and concentrate the sun’s energy upon a water boiler, heating it to more than 1,000 degrees. This generates steam, which in turn drives a turbine to generate electricity. Plants will consist of clusters of these “solar fields”, with each tower producing 20 megawatts of power. BrightSource predicts that the plants’ large scale, low production cost, and relative reliability will allow them to compete with carbon fuels on price point.
The first plant is scheduled for a 2011 opening in Ivanpah, California, and should produce 246,000 megawatt hours of renewable electricity per year. As many as 4 plants will follow as permits and infrastructure allow. Brightsource Energy’s president John Woolard states “From what I know, this is the biggest commitment ever in the history of solar”.